Risks of Nontraumatic Lower-Extremity Amputations in Patients with Type 1 Diabetes
A population-based cohort study in Sweden
Article Figures & Tables
Figures
- Figure 1—
The cumulative probability of nontraumatic LEA among type 1 diabetic patients, estimated by the Kaplan-Meier method.
Tables
- Table 1—
Characteristics of the patients hospitalized at least once for type 1 diabetes, 1975–2004, Sweden
Women Men Total n 15,001 16,353 31,354 Age at enrollment (years) 19.9 ± 11.3 19.6 ± 11.1 19.7 ± 11.1 Mean calendar year at entry 1990 1991 1991 Follow-up duration (years) 13.1 ± 7.6 12.0 ± 7.4 12.5 ± 7.5 Person-years accumulated 196,928 196,206 393,134 Patients with (%) Ophthalmic complications* 20.6 16.4 18.4 Diabetic nephropathy† 9.2 8.5 8.8 Neurological complications‡ 7.1 7.1 7.1 No. of nontraumatic LEAs§ 201 264 465 Amputation above knee 18 11 29 Amputation below knee 82 111 193 Amputation below ankle 101 142 243 Age at diagnosis (years) 45.1 ± 7.6 45.6 ± 8.1 45.4 ± 7.8 -
Data are means ± SD unless indicated otherwise.
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↵* Ophthalmic complications defined by ICD-7 codes 260.20, 260.21, and 260.29, ICD-8 codes 250.01, 250.02, and 250.03, ICD-9 code 250E, and ICD-10 codes E10.3, E11.3, E12.3, E13.3, and E14.3.
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↵† Diabetic nephropathy defined by ICD-7 code 260.30, ICD-8 code 250.40, ICD-9 code 250D, and ICD-10 codes E10.2, E11.2, E12.2, E13.2, and E14.2.
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↵‡ Neurological complications defined by ICD-7 codes 260.40 and 260.49, ICD-8 code 250.05, ICD-9 code 250F, and ICD-10 codes E10.4, E11.4, E12.4, E13.4, and E14.4.
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↵§ LEA defined by the operation code: amputation below the ankle was defined by operation codes 8750 or 8760 before 1998 and NHQ16, NHQ17, NHQ12, NHQ13, NHQ14, or NHQ99 afterwards; amputation above the ankle but below the knee was defined by operation codes 8770 or 8771 before 1998 and NGQ19, NHQ09, NHQ11, or NGQ99 afterwards; and amputation above the knee was defined by operation codes 8780 or 8781 before 1998 and NGQ09, NFQ19, or NFQ99 afterwards. Traumatic amputations of the lower-extremity were excluded.
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- Table 2—
RRs (95% CIs) for nontraumatic LEAs, according to calendar period at follow-up, sex, and attained age, among patients hospitalized at least once for type 1 diabetes, 1975–2004, Sweden
All nontraumatic LEAs Amputation above knee Amputation below knee but above ankle Amputation below ankle Obs* RR (95% CI) Obs RR (95% CI) Obs RR (95% CI) Obs RR (95% CI) Calendar period at follow-up 1975–1999 307 Reference 21 Reference 132 Reference 154 Reference 2000–2004 158 0.6 (0.5–0.8) 8 0.5 (0.2–1.3) 61 0.5 (0.4–0.7) 89 0.7 (0.5–0.9) Sex Male 264 Reference 11 Reference 111 Reference 142 Reference Female 201 0.7 (0.5–0.8) 18 1.5 (0.7–3.1) 82 0.6 (0.5–0.8) 101 0.6 (0.5–0.8) Attained age (years) <40 126 Reference 12 Reference 37 Reference 77 Reference 40–49 204 9.7 (7.7–12.1) 12 5.8 (2.6–12.9) 94 15.4 (10.5–22.6) 98 7.5 (5.6–10.1) 50–59 121 21.3 (16.5–27.5) 4 7.4 (2.3–23.4) 59 37.1 (24.4–56.5) 58 16.1 (11.3–22.8) ≥60 14 42.9 (24.3–75.6) 1 33.7 (4.0–280.8) 3 34.7 (10.5–114.7) 10 45.9 (23.2–90.9) Ptrend <0.0001 <0.0001 <0.0001 <0.0001 -
Variables listed in the table were mutually adjusted.
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↵* Obs, number of observed nontraumatic LEAs in each category.
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